If $f_a$ and $f_f$ represent the carrier wave frequencies for amplitude and frequency modulations respectively,then

In a communication system,the process of superimposing a low-frequency signal on a high-frequency wave is known as:

The size of the antenna required for a carrier wave of frequency $3 \text{ MHz}$ is: (in $\text{ m}$)

An antenna is mounted on a $400 \; m$ tall building. What will be the wavelength of the signal that can be radiated effectively by the transmission tower up to a range of $44 \; km$? (In $m$)

In $AM$ modulation,a signal is modulated on a carrier wave such that maximum and minimum amplitude are found to be $6\,V$ and $2\,V$ respectively. The modulation index is $\dots \%$.

$A$ signal of frequency $3 \text{ kHz}$ is amplitude modulated on a carrier wave of frequency $2.5 \text{ MHz}$. The upper and lower sideband frequencies in the resultant signal are